The present invention relates to an endoscope and, more particularly, to a disposable liquid supply system for use with an endoscope.
The development of endoscopic instruments has greatly enhanced our ability to diagnose and treat diseases in relatively inaccessible regions of the body. The first examinations that could be considered "endoscopic" in the modern sense were probably the rectal inspections conducted in the 18th century. The physician peered through a rigid tube inserted into the patient's rectum and relied on candles or gas lamps to illuminate the interior. By today's standards the physician saw very little; however, endoscopic examinations continued and endoscopes of various designs were invented.
In 1932, Schindler introduced the semi-flexible gastroscope. This device was easier and safer to insert than prior endoscopes, and it offered sharper images and a wider field of view allowing visualization of about seventy-five percent of the gastric mucosa. The instrument could also be fitted with a camera and with a channel for the insertion of biopsy forceps. The Schindler semi-flexible endoscope was used until the late 1950's.
Although accessories for the semi-flexible instruments were continually improved, the landmark development in endoscopy was the incorporation of fiberoptic principles into endoscopic design. Hirschowitz produced the first fiberoptic gastroscope in 1958. This completely flexible instrument was inserted with much less discomfort to the patient. Because of its maneuverability, it could reveal a duodenum and other areas that were previously inaccessible to rigid endoscopes.
The two outstanding features of the fiberoptic endoscope are its flexibility and excellent viewing ability. Light travels down the individual glass fibers and emerges at the distal end hardly diminished in intensity. There, a lens system focuses the light and fuses the image, and a set of 20,000 to 30,000 integrated fibers returns the image to the proximal end of the instrument, where the image is magnified. With fiberoptic endoscopes, images are not reversed. The "cold" illumination, produced by filtering out the heat component of the light, does not harm the organ being visualized. The light sources are also adaptable for both movie and still photography and for electronic video recording.
The development of the endoscope will continue indefinitely. The fiberoptic technology is now being replaced in some cases by a direct video imaging system which includes a CCD camera at the distal end of the endoscope tube. This arrangement is an expansion and it permits a reduction in the diameter of the tube.
As is well known, endoscope tubes also include mechanisms for turning the tip in four directions (up, down and to each side) to facilitate passage of the instrument around angles and allow visualization of all surfaces. An additional viewing channel, coupled to a separate eye piece, for simultaneous, direct viewing by a second observer is also available. In addition, the tubes contain channels for air insufflation, water instillation (so that lenses can be cleaned during a procedure) and to allow passage of biopsy instruments and fulguration instruments. Tube channels may also be provided for passage of laser beam devices, spray catheters and polypectomy snare wires.
A typical endoscope, as found in a physician's office or hospital, is used repeatedly over the course of a given day. The endoscope tube must be completely sterilized between each use to avoid the transmission of diseases, such as AIDS, Hepatitis, etc. Typically, a sterilization fluid is passed through the water and air ducts of the instrument to sterilize the internal surfaces. This sterilization fluid is at times supplied from a bottle which temporarily replaces the water bottle used with the endoscope.
Until now, the water supply for an endoscope has comprised a separate, sterilizable water bottle which is removably attached to the endoscope control unit and connected by separate air and water lines and a quick disconnect coupling to the endoscope supply cable. Water is "pumped" from the water bottle by supplying air under pressure through the air supply line to the top of this bottle.
The water bottle, which is substantially rigid, is refillable with fresh water by removing the cap.
Although the fresh water added to an endoscope water bottle may be sterile, the bottle itself may become contaminated during use by microscopic organisms which pass into the water bottle through the air or water supply tubes. Sterilization of supply tubes and the water bottle itself is thus desirable between each use. Not only is such sterilization time consuming for a physician's or hospital's staff, but failure to properly sterilize the tubes and the bottle results in a possible risk of patient infection.